Biology subjects

Sang, X.

Publications and source records attributed to Sang, X..

3 recordsLinked to original sources

bioRxiv2022

Protein Lactylation and Metabolic Regulation of the Zoonotic Parasite Toxoplasma gondii

The biology of Toxoplasma gondii, the causative pathogen of one of the most wide-spread parasitic diseases remains poorly understood. Lactate, which is derived from glucose metabolic pathways, is considered to be not only an energy source in a variety of organisms including Toxoplasma gondii, but also a regulatory molecule that participates in gene activation and protein functioning. Lysine lactylation is a type of posttranslational modifications (PTMs) that was recently associated with chromatin remodeling, but lysine lactylation of histone and non-histone proteins has not yet been studied in T. gondii. To examine the prevalence and function of lactylation in T. gondii parasites, we mapped the lactylome of proliferating tachyzoite cells and found 1964 lactylation sites on 955 proteins in the T. gondii RH strain. The lactylated proteins were distributed in multiple subcellular compartments and were closely related to a wide variety of biological processes, including mRNA splicing, glycolysis, aminoacyl-tRNA biosynthesis, RNA transport, and multiple signaling pathways. We also performed chromatin immunoprecipitation sequencing (ChIP-seq) analysis with a lactylation specific antibody, the results revealed that histone H4K12la and H3K14la were enriched in the promoter and exon regions of Toxoplasma gondii genes associated with microtubule-based movement and cell invasion. We further confirmed the de-lactylase activity of histone deacetylase TgHDACs 2, 3, and 4, and that treatment with anti-histone acetyltransferase (TgMYST-A) antibodies profoundly reduced protein lactylation in the parasites. This study offers the first dataset of the global lactylation proteome and provides a basis for further dissection of the functional biology of Toxoplasma gondii.

microbiology↗

bioRxiv2022

A Chitin-Binding Protein Ultra-highly expressed in the Outer Fold of Mantle is Related to Shell Colour in Pacific Oyster Crassostrea gigas

Molluscs constitute the second largest phylum of animals in the world, and shell colour and stripes are one of their most important phenotypic characteristics. Studies on the mechanism of shell pigmentation help understand the evolutionary and ecological significance of shell colour and serve as the basis for shell colour breeding. In this study, a matched-pair design was used in comparing the black- and white-striped mantles of the same oyster. The result showed that the stripes of shell surface are corresponding to the stripes of the mantle edge. Transcriptomic analysis identified an uncharacterized protein gene (we named it as Crassostrea gigas chitin-binding protein, CgCBP) highly expressed in the black mantles. Three folds (inner fold, middle fold and outer fold) were found on the mantle edge of oyster, but only the outer fold has the same colour as the shell. Transcriptomic comparison indicated that the three folds of the mantle edge are functionally differentiated, and the CgCBP gene is ultra-highly expressed only in the outer fold. We obtained new black and white shell periostraca from the shell notching experiment and found their structural differences by scanning electron microscope. Chitin was successfully extracted and identified from the shell periostraca. Proteomic analysis revealed differences in protein composition between the two shell periostraca. Particularly, the black shell periostraca have more proteins related to melanin biosynthesis and chitin binding compared with the white ones, and melanin particles were observed in the black mantle edge using transmission electron microscope. Magnetic bead binding and Western blot experiments showed that the CgCBP protein can specifically bind to chitin and in vivo RNAi screening indicated that CgCBP knockdown can change the structure of the shell periostracum and reduce its pigmentation. All these results suggest that the outer fold of mantle may have more important roles in shell pigmentation, shell periostracum structure is functionally correlated with shell pigmentation, and the CgCBP gene ultra-highly expressed in the outer fold may influence shell pigmentation by affecting its periostracum structure.

physiology↗

bioRxiv2022

Control of Leaf Width by the APC/CTAD1-WL1-NAL1 Pathway in Rice

Leaf morphology is one of the most important features of the ideal plant architecture. However, the genetic and molecular mechanisms controlling leaf morphology in crops remain largely unknown, despite their central importance. Here we demonstrate that the APC/CTAD1-WL1-NAL1 pathway regulates leaf width in rice, and mutation of WL1 leads to width leaf variation. WL1 interacts with TAD1 and is degraded by APC/CTAD1, with the loss of TAD1 function resulting in narrow leaves. The WL1 protein directly binds to the regulatory region of NAL1 and recruits the corepressor TOPLESS-RELATED PROTEIN to inhibit NAL1 expression by down-regulating the level of histone acetylation of chromatin. Furthermore, biochemical and genetic analyses revealed that TAD1, WL1, and NAL1 function in a common pathway to control leaf width. Our study establishes an important framework for the APC/CTAD1-WL1-NAL1 pathway-mediated control of leaf width in rice and introduces novel perspectives for using this regulatory pathway for improving crop plant architecture.

plant biology↗